Automatic sewing machine exclusively used for sewing zipper on workpiece

ABSTRACT

This invention relates to an automatic sewing machine exclusively used for sewing a zipper on a workpiece and its related art. The automatic sewing machine exclusively used for sewing a zipper on a workpiece comprises a sewing machine (10,20) capable of at least sewing linearly, a drive device movable in two axes right angles to each other in a plane vertical to the movement direction of the needle (11, 21) of the sewing machine and a zipper setting device (12, 22) attached to said drive device for gripping said zipper (3) and workpiece (1) in a predetermined relationship.

TECHNICAL FIELD

This invention relates to an automatic sewing machine exclusively usedfor sewing a zipper on a flapped product, for example, a workpiece to besewn such as a skirt or the like and to a related art thereof.

BACKGROUND TECHNOLOGY

The conventional sewing process will be describe by way of the sewing ofa zipper on a skirt. FIGS. 1(A)-(C) show three different types of flaps(each of which is the portion of the skirt covering the zipper) of aworkpiece. FIGS. 2(A) and (B) are exploded perspective and right-handside elevational views, respectively, of a workpiece without a liningsewn thereon and FIGS. 3(A) and (B) are exploded prespective andright-hand side elevational views, respectively, of a workpiece with alining sewn thereon which show relationship between parts of theworkpieces, respectively.

In these FIGS., 1 is the surface cloth, 2 is the lining, 3 is the zipperhaving the slider 3a and fastener tapes 3b, 3b and 4 is the flap of theworkpiece 1. There are three different types of flaps as shown in FIGS.1(A)-(C).

As shown in FIGS. 2(A) and 3(A), the zipper 3 is sewn by the sewingwidth L on the surface cloth 1a which is unlined or lined. FIGS.4(A)-(F) show the conventional sewing process when the flap is a leftflap. FIG. 4(A) shows the initial sewing step in which the slider 3a isretracted to substantially the central area of the length of the zipper3. As shown in FIG. 4(A), the operator starts to sew the zipper 3 on theworkpiece at the leading left-hand side corner thereof with his bothhands placed on the surface cloth 1 on the opposite sides of the zipper3. After the flap has been sewn at its inner side edge on the zipper 3halfway in the longitudinal direction of the zipper 3, the sewingmachine 10 is once stopped and the slider 3a is pulled to the leadingend of the zipper (FIG. 4(B)). This is to prevent the needle 11 frominadvertently interfering with the slider 3a. The sewing operation thencontinues to a predetermined position in the longitudinal direction ofthe zipper and the workpiece is rotated by 90° in the arrow directionwith the needle held in its lowered position (FIG. 4(C)). The sewingoperation progresses along the trailing end of the zipper 3 by thesewing width L and the workpiece is again rotated by 90° in the arrowdirection with the needle held in its lowered position (FIG. 4(D)).After the lower side of the free end portion of the flap 4 has been sewnon the zipper halfway in the longitudinal direction of the zipper whileturning the flap over, the sewing machine 10 is stopped and the slider3a of the zipper 3 is moved back to substantially the central area ofthe length of the zipper 3 (FIG. 4(E)). Thereafter, the sewing operationis resumed to continue to sew the flap to a predetermined position inthe longitudinal direction of the zipper whereupon thread cutting iseffected to complete the sewing operation (FIG. 4(F)).

Since the sewing process is basically conducted manually by theoperator, the process has the following drawbacks:

(I) The surface cloth and zipper (or lining) tend to displace relativeto each other.

(II) The manipulation of the slider is troublesome.

(III) The formed seam or seams tend to be meandering.

(IV) The sewing width is not uniform.

(V) Safety in the sewing operation is not assured.

(VI) A highly skilled hand is required to obtain a final sewn product ofhigh quality.

The present invention has been developed to eliminate the drawbacksinherent in the above-mentioned prior art and a first object of thepresent invention is to provide an automatic sewing machine exclusivelyused for sewing a zipper on a workpiece automatically and precisely.

Another object of the present invention is to provide a process forsewing a zipper on a workpiece safely and effectively by the use of anautomatic sewing machine designed to exclusively carry out the process.

A further object of the present invention is to provide a cassette typezipper setting device adapted to be detachably attached to an automaticsewing machine exclusively used for sewing a zipper on a workpiece fortemporally setting the zipper and the workpiece.

A further object of the present invention is to provide a flapturning-over device adapted to automatically turn the flap over when thelower side of the flap is sewn by the sewing machine.

A further object of the present invention is to provide theconfiguration of an intermediate holding-down member to cooperate withthe above-mentioned flap turning-over device for acceleration of theflap turning-over as the lower side of the flap is sewn and foreffectively holding a workpiece as the needle is pulled out of theworkpiece.

DISCLOSURE OF THE INVENTION

A first aspect of the present invention resides in an automatic sewingmachine exclusively used for sewing a zipper on a flapped workpiece. Theapparatus includes a drive device movable in two directions at rightangles to each other and a zipper setting device attached to the drivedevice for holding the zipper and workpiece in a predeterminedrelationship to each other.

In another preferred embodiment of the invention, the zipper settingdevice is detachably attached to the abovementioned drive device In thisembodiment, the zipper and workpiece are held in position by a springdisposed in a predetermined position externally of the sewing machine.

In a further preferred embodiment of the invention, a zipperholding-down leaf spring is provided for positively holding the zipperin position.

A second aspect of the invention resides in a process for sewing azipper on a flapped workpiece by the use of an automatic sewing machineexclusively designed for the purpose. A zipper having a length longerthan a length required by the length of the slider is gripped with aflapped workpiece and with the slider projecting outwardly beyond theworkpiece. The zipper and flapped workpiece are moved in a planevertical to the movement direction of the sewing machine needle inresponse to the operation of the sewing machine while gripping thezipper and flapped workpiece to thereby sew the inner edge of the flapin linearly longitudinal and transverse directions. The flap is turnedover. The zipper and flapped workpiece are then moved substantiallylinearly relative to the sewing machine needle while holding the zipperand workpiece to thereby sew the lower side of the flap longitudinallylinearly. The sewing machine is stopped and the thread is cut. Theworkpiece having the zipper sewn thereon is removed from the sewingmachine. The zipper is retracted to an intermediate position in thelongitudinal direction of the zipper. The portion of the fastener tapesprojecting outwardly beyond one edge of the sewn product are then cut. Astopper is fastened to the zipper in a predetermined position adjacentto the leading end of the zipper.

The preferred mode of the process of the invention further includes thestep of sewing the prepared zipper on the lining with the slider thereofprojecting outwardly beyond one end edge of the lining and theabove-mentioned gripping step consisting of gripping the zipper andsurface cloth with the slider projecting outwardly beyond the alignedend edges of the lining and surface cloth.

Another preferred mode of the process of the invention includes thesteps of gripping the zipper and workpiece by a cassette type zippersetting device which is separate from the sewing machine and ofdetachably attaching the setting device to support means movable inbiaxial directions in a plane vertical to the movement direction of thesewing machine needle.

A third aspect of the invention resides in a cassette-type zippersetting device detachably attached to a drive device relatively movablein biaxial directions in a plane vertical to the movement direction ofthe sewing machine needle. A platform having an attachment portion isattached to the sewing machine drive device. A zipper holding-downmember is provided adjacent an opening in the platform to detachablyhold a zipper in a predetermined position on the platform. A workholding-down mechanism is provided on the platform to removably hold theworkpiece in a predetermined position relative to the zipper.

In the preferred embodiment described just above, the above-mentionedattachment portion of the platform comprises a pair of side edgesadapted to slide into guide grooves formed in the above-mentionedsupport means.

In another preferred embodiment of the invention the above-mentionedzipper holding-down member comprise a pair of holding-down leaf springsin the form of ski plate provided on the opposite sides of the openingin the platform.

In a further embodiment of the invention, the above-mentioned workpieceholding-down mechanism is designed to independently hold the workpieceon the opposite sides of the opening in the platform. The workpieceholding-down mechanism further comprises a lever securing plate securedto the above-mentioned platform and having a slot, a workpieceholding-down plate rockably attached to the above-mentioned platform, alever rockably attached to the above-mentioned platform in coaxial withthe above-mentioned workpiece holding-down plate and a projectionadapted to enter the above-mentioned slot in the lever securing plate tohold the workpiece holding-down plate and a spring acting between theabove-mentioned workpiece holding-down plate and lever to urge them awayfrom each other.

A fourth aspect of the invention resides in a flap turning-over deviceadapted to automatically turn the flap over as the sewing machine sewsthe lower side of the flap. A signal producing device is adapted tosignal when the sewing operation on the sewing machine has proceeded tothe step for sewing the lower side of the flap. A flap-turning-overmember contacts the flap to turn the flap over. A drive mechanism causesthe flap-turning-over member to move vertically in response to a signalfrom the signal producing device.

In the preferred embodiment of the invention described just above, thedrive mechanism comprises a first actuator for moving theabove-mentioned flap-turning-over member vertically and a secondactuator for moving the flap-turning-over member horizontally. In thisembodiment, the flap-turning-over member first moves vertically and thenhorizontally in a direction to turn the flap over when the lower end ofthe flap-turning-over member is positioned below the free end of theflap in a further preferred embodiment of the invention, theflap-turning-over member is designed to effect a curved, elliptical,circular or parabolic movement.

A fifth embodiment of the invention resides in an intermediateholding-down member having a certain thickness in the shape of a shipand the longer axis extending in the advance movement direction of theworkpiece for positively holding the workpiece down as the sewing needleclears the workpiece when the sewing machine sews the lower side of theflap. A needle receiving through slot is formed substantially in thecenter of the member and has the lower axis extending in the longer axisdirection of the slot. A leading end portion deflects the flap towardthe left-hand side or right-hand side of the intermediate holding-downmember. A flap guide is moved on the opposite sides of the intermediateholding-down member. A flap guide is moved on the opposite sides of theintermediate holding-down member for assisting the turning-over of theflap deflected towards the left-hand or right-hand side of the member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view showing two different forms of flaps;

FIGS. 2(A) and (B) are exploded perspective and right-hand sideelevational views, respectively, showing relative relationship betweencomponents of a workpiece without a lining;

FIGS. 3(A) and (B) are exploded perspective views showing relativerelationship between components of a lined workpiece;

FIGS. 4(A)-(F) are schematic views showing the conventional sewingprocess;

FIG. 5 is a perspective view of the principal parts of one embodiment ofthe automatic sewing machine exclusively used for sewing a zipper on aworkpiece according to the present invention;

FIGS. 6 and 7 are plan and front elevational views, respectively, of theprincipal parts of the sewing machine of FIG. 5 showing them after thezipper has been sewn on the workpiece;

FIG. 8 is a perspective view of another embodiment of the automaticsewing machine exclusively used for sewing a zipper on a workpieceaccording to the present invention;

FIG. 9 is a perspective view of the cassette type zipper setting deviceemployed in the automatic sewing machine of FIG. 8;

FIG. 10 is a detailed perspective view of the head of the automaticsewing machine exclusively employed in the automatic sewing machineaccording to the present invention;

FIG. 11 is a block diagram of the pneumatic circuit of the flapturning-over device as shown in FIG. 10;

FIG. 12 is a schematic view explaining the operation of the flapturning-over device of FIG. 10;

FIG. 13 is a schematic front elevational view for explaining theoperation of another embodiment of the flap turning-over device;

FIGS. 14(A)-(C) are plan, front elevational and right-hand sideelevational views, respectively, of the intermediate holding-down memberas shown in FIG. 10;

FIG. 15 is a perspective view of another embodiment of the intermediateholding-down member;

FIGS. 16(A)-(D) are plan, front elevational, righthand side elevationalviews, respectively, of the intermediate holding down member of FIG. 15and a vertically cross-sectional view taken along the line D--D of FIG.16(B);

FIG. 17 is a schematic block diagram of the essential portion of thehardware;

FIG. 18 is a schematic view of the operation table; and

FIG. 19 is a flow chart showing the operation of the automatic sewingmachine exclusively used for sewing a zipper on a workpiece according tothe present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 5, there is shown principal parts of the automaticsewing machine exclusively used for sewing a zipper on a workpiece in aperspective view.

The sewing machine 10 is a conventional sewing machine which is capableof at least linearly sewing as shown by the broken line in the plan viewof FIG. 6. An X - Y axis drive device D is attached to the sewingmachine and drives the arm 13 in the X - Y axes right angles to eachother in a plane vertical to the movement direction of the sewingmachine needle 11. A zipper setting device 12 is detachably or fixedlyattached by means of its attachment portion 12a to the arm 13 of the X -Y axis drive device D. The zipper setting device 12 also comprises abase or platform 12b supporting a workpiece, for example, the surfacecloth 1 of a skirt. Provided in the platform 12b at substantially thecentral area thereof is a through opening 12c through which the sewingmachine needle 11 passes. The platform 12b of the zipper setting device12 is provided with a pair of holding-down members 18 along the oppositesides of the opening 12c. In the illustrated embodiment, the zipperholding-down members are formed of a pair of holding-down leaf springsin the shape of a ski plate secured at the inner ends thereof to theplatform 12b. It will be apparent to those skilled in the art that thesame purpose can be attained by various other arrangements. The zippersetting device 12 is also provided with a pair of holding-down plates 17urged against the zipper holding-down members 18 through a shaft 15fixedly secured to a link 14 and rotatably journalled on the platform12b for rotation with respect to the platform 12b and a pair of levers16 fixedly secured to the opposite ends of the shaft against rotation.The above-mentioned surface cloth 1 of the skirt is placed onto thezipper holding-down members 18 after the zipper 3 having the lining 2sewn thereto or without the lining been sandwiched between the platform12b and zipper holding-down members 18. Thus, when the actuator orsolenoid is energized, the surface cloth 1 is positively held betweenthe zipper holding-down members- 18 and holding-down plates 17. In orderthat the surface cloth 1 and zipper 3 will not displace relative to eachother during the sewing operation, various arrangements are provided.For example, the inner side edge 17a of the holding-down plate 17 may bebent downwardly by a small amount (FIG. 5), the surface of theholding-down plate which comes to contact the surface cloth may beapplied thereto a slip-resistance tape made of rubber or the like or theundersurface of the downwardly bent inner side edge of the holding-downplate may be knurled (FIG. 10). After the zipper 3 and surface cloth 1have been positively held in the zipper setting device in the mannermentioned just above, the sewing machine 10 and X - Y axis drive deviceare driven to sew the zipper on the surface cloth.

The zipper sewing-on process according to the present invention includesthe step in which the zipper 3 having a length longer than a requiredlength by an amount corresponding to the length of the slider 3a thereofand the surface cloth 1 of a workpiece such as a skirt, for example, areheld down by the above-mentioned zipper setting device 12 or the likewith the slider projecting outwardly beyond the end of the surfacecloth. With the zipper and surface cloth positively held down by thezipper setting device, the sewing machine 10 is operated and the surfacecloth and zipper are moved relative to each other so as to describe anL-shape in a plane vertical to the movement direction of the sewingneedle 11 to thereby form a longitudinal straight seam 19a along theinner side edge of the flap and a transverse straight seam 19 b (seeFIG. 6). The sewing-on process of the present invention includes thestep in which a longitudinal straight seam 19c is formed along the lowerside of the free side edge of the flap by moving the flap parallel tothe seam 19a while turning the flap over with the zipper 3 and skirtsurface cloth 1 positively held against movement. After the sewingmachine 10 has been stopped and thread cutting has been effected, theskirt having the zipper sewn thereon is removed out of the sewingmachine. Thereafter, the slider 3a is retracted halfway in thelongitudinal direction of the zipper 3, the portion of the fastenertapes 3b projecting outwardly beyond the end of the skirt is cut off anda stopper is fastened to the zipper in a predetermined position thereofto thereby complete the zipper having a proper length. According to thezipper sewing-on process of the present invention, since the slider 3ais not present at the area where the needle 11 of the machine 10 passeswhile the zipper 3 is being sewn on the skirt in this way, interferencebetween the slider 3a and needle 11 can be perfectly avoided. FIG. 7shows the condition immediately after the completion of sewing of thezipper 3 on the surface cloth 1 by the sewing machine needle.

FIG. 8 shows another embodiment of the automatic sewing machineexclusively used for sewing a zipper on a workpiece according to thepresent invention. The sewing machine 20 of this embodiment is identicalwith the sewing machine 10 shown in FIG. 5 with respect to fundamentalstructure. That is, the arm 23 of the X - Y axis drive device (notshown) attached to the sewing machine 20 is designed to freely drivesupport means 26 in a plane perpendicular to the movement direction ofthe needle 21 which support means is designed to support the detachablecassette type zipper setting device 22. The support means 26 comprises apair of opposing guide grooves 26a into which the zipper setting device22 slides to be held in a predetermined position and an opening 26bthrough which the sewing machine needle 21a can pass. As in the case ofthe sewing machine 10 of FIG. 5, the support means 26 also comprises alinkage 25 and holding-down plates 24 for positively holding the zippersetting device 22 received in the support means in position.

Details of the cassette type zipper setting device 22 are shown in FIG.9. The zipper setting device 22 includes a platform 22b having sideedges 22a adapted to be received in the pair of guide grooves 26a in thesupport means 26 driven by the X - Y axis drive device D. Formed in theplatform 22b in the position in alignment with the opening 26b in thesupport means 26 is an opening 22c. Zipper holding-down members 22d arefixedly secured to the platform 22b and have the same construction asthe zipper holding-down members 18 shown in FIG. 5. The zipper settingdevice 22 further comprises workpiece holding-down mechanisms adapted toremovably hold the surface cloth 1 of a workpiece such as a skirt, forexample, on the platform 22b in a predetermined position with respect tothe zipper 3. In the illustrated embodiment, the right-hand andleft-hand side workpiece holding-down mechanisms operate independentlyof each other. The workpiece holding-down mechanism comprises a leversecuring plate 22f fixedly secured to the inner end of the platform 22band having a slot 22e, a holding-down plate 22g attached to the platform22b for rocking movement relative to the platform, a lever 22j attachedto the platform 22b in coaxial with the holding-down plate 22g forrocking movement relative to the platform and having a projection 22iadapted to enter the slot 22e in the lever securing plate 22f to holdthe holding-down plate 22g in a predetermined position and a coil spring22k mounted to bias the holding-down plate 22g and lever 22j away fromeach other.

When the sewing machine 20 having the detachable zipper setting device22 which is the second embodiment of th present invention is employed,the sewing-on process as described hereinabove further includes the stepin which the zipper 3 with or without the lining 2 and the skirt surfacecloth 1 are positively held in position in the zipper setting device 22by the use of a platform 28 fixedly secured to a table 27 positionedexternally of the sewing machine, for example and the zipper settingdevice 22 having the zipper and surface cloth held therein is thendetachably attached to the support means 26.

The process makes it possible to preliminarily hold the zipper 3 andsurface cloth 1 using the platform 28 during the sewing operation of thesewing machine 20 and replace the zipper setting device 22 upon thecompletion of the sewing operation to thereby substantially enhanceoperation efficiency. And when zipper setting devices 22 having aplurality of parts of different sizes are in stock, the sewing machinecan easily accommodate different sewing operations. And since the secondembodiment of the sewing machine is different from the sewing machine 10of FIG. 5 in which the zipper 3 an surface cloth 1 are directly held inthe machine, the second embodiment of the sewing machine has theadvantage that the zipper and surface cloth will not substantially getout of position relative to each other and/or bend and thus, theobtained product has a high quality.

Referring to FIG. 10, there are shown a flap turning-over device 31adapted to automatically turn the flap 4 over when the lower side of thefree side edge of the skirt flap 4, for example, is sewn and anintermediate holding-down and drive mechanism having an intermediatepressure foot 61 adapted to positively hold the skirt surface cloth 1down when the needle clears the surface cloth and assist theturning-over of the flap and having a thick substantially ship-shape andthe longer axis extending in the advancing direction of the skirt.

FIG. 11 shows the air pressure circuit for the flap turning-over device31 and FIGS. 12(A)-(C) schematically show the operation of the flapturning-over device 31. The illustrated flap turning-over device 31comprises a first cylinder 33 for moving a flap turning-over portion 32in the X axis direction as shown, a second cylinder 34 for moving theflap turning-over portion 32 vertically and a connector plate 35connecting between the two cylinders. In the illustrated air pressurecircuit, 36 is a five-port and two-position change-over valve, 37 is athree-port and two-position change-over valve, 38 is a flow regulatorvalve with a check valve and 39 is an air pressure supply source.

When the five-port and two-position change-over valve 36 is shifted fromthe position of FIG. 11 to the upper circuit, compressed air from theair pressure supply source 39 flows via a line 40 and its branch line40a into the three-port and two-position change-over valve 37 andfurther through a line 42 into the cylinder chamber of the secondcylinder 34. Thus, the flap turning-over portion 32 is lowered (FIG.12(A)), but when the flap turning-over portion 32 reaches the bottomdead point (FIG. 12(B)), pressure rises in the lines 40a, 40b and 42.When the pressure exceeds a predetermined set value, the compressed airflows through the flow regulator valve 38 with a check valve into theline 40c and is supplied into the first cylinder chamber 33a of thefirst cylinder 33 whereby the connector plate 35 secured to the pistonrod associated with the first cylinder 33 and accordingly, the secondcylinder 34 secured to the connector plate and the flap turning-overportion 32 move leftwards as shown in FIG. 11 and the flap turning-overportions 32 turns the flap 42 over.

When the five-port and two-position change-over valve 36 is shifted tothe lower circuit and simultaneously, the three-port and two-positionchange-over valve 37 is shifted to the lower circuit, compressed airsupplied into the line 41 flows through the line 41a, change-over valve37 and line 42 into the second cylinder 34 and then through the line41b, flow regulator valve 38 and line 41c into the second chamber 33b ofthe first cylinder 33 whereby the flap turning-over portion 32 movesrightwards as shown in FIG. 11 at its bottom dead point. Finally, whenthe three-port and two-position change-over valve 37 is shifted to itsupper circuit, the line 42 is evacuated through the lines 40a, 40 andfive-port and two-position change-over valve 36 and in fluidcommunication resulting in rapid reduction in air pressure. Thus, thepiston rod in the second cylinder 34 is raised under spring pressure andaccordingly, the flap turning-over portion 32 is caused to rise.

FIG. 13 is a side elevational view of another embodiment of the flapturning-over device.

In FIG. 13, 50 is a flap turning-over device, 51 is an air pressureactuator or solenoid operated operation rod attached to the sewingmachine 10 (20), 52 is a first drive lever pivoted at one end to theoperation rod 51 and rockably journalled in a support member 53suspended from the head of the sewing machine, 54 is a second drivelever pivoted at one end to the other end of the first drive lever 52and 55 is a flap turning-over portion attached to the other end of thesecond drive lever 54. The second drive lever 54 has a slot 54a atsubstantially the central area thereof for receiving a stub shaft 56provided on the support member 53 right below and in parallel to theshaft of the first drive lever 52. Thus, the second drive lever 54 canrock about the stub shaft 56 while sliding on the stub shaft. Thus, thelower end of the flap turning-over portion 55 secured to the other endof the second drive lever 54 moves elliptically as the operation rodmoves reciprocally.

And the flap turning-over device may be of various arrangements such asthose in which the lower end of the flap turning-over portion movescircularly or parabolically other than the illustrated one.

FIGS. 14(A)-(C) are plan, front elevational and right-hand sideelevational views, respectively, of the intermediate pressure foot 61shown in FIG. 10. The intermediate pressure foot 61 comprises a slot61a, a leading end portion 61b adapted to deflect the flap towards theright-hand or left-hand side of the intermediate pressure foot 61 andflap guides 61c formed in the opposite sides of the intermediatepressure foot for turning the deflected flap over. The needle 11 (21) ofthe sewing machine 10 (20) can extend through the slot 61a in theintermediate pressure foot 61. When the longitudinal straight seam 19aand the transverse straight seam 19b are formed on the flap as shown inFIG. 6, like the conventional pressure foot, the inventive intermediatepressure foot 61 acts to hold a workpiece so that when the needle 11clears the workpiece, the workpiece will not be lifted due to itsfrictional resistance to the needle 11 and thus will not interfere withthe formation of the seams. On the other hand, when the seam 19c isformed on the lower side of the free side edge of the flap 4, as shownin FIG. 10, the sewing machine sews the zipper 3 and the workpiecetogether while the flap turning-over device 31 (50) is turning the flap4 over. At this time, the intermediate pressure foot 61 guides the endedge of the flap turned over by the flap turning-over device along theflap guides 61c so as to prevent the flap 4 from turning back onto thezipper 3 while the sewing operation.

FIG. 15 is a perspective view of another embodiment of the intermediatepressure foot, FIGS. 16(A)-(D) are plan, front elevational, right-handside elevational views, respectively, of the intermediate pressure footand a longitudinally sectional view taken along the line D--D of FIG.16(B).

The intermediate pressure foot 62 has a substantially elliptical shapeand comprises a slot 62a, a leading end portion 62b and flap guides 62cformed in the opposite sides of the pressure foot. As shown in FIG.16(C), the flap guide 62c has a groove-shaped cross section and slopesupwardly by a small degree towards the rear of the pressure foot. Thus,the turning-over of the flap is accelerated.

Now, the intermediate pressure foot drive mechanism 10 for driving theabove-mentioned pressure foot 61 (62) will be described referring toFIG. 10. 67 is a cylinder pivoted at one end to the head of the sewingmachine 10 and the piston rod 67a of the cylinder supports anintermediate pressure bar 63 having the intermediate pressure foot 61(62) at the lower end of the bar through a platform 64. 66 is a cammember secured to the head of the sewing machine and having a cam groove66a for guiding a guide shaft 65 secured to one end face of the platform64. The cam groove has such a shape that as the piston rod 67a of thecylinder 67 moves downwardly, the intermediate pressure foot 61 (62)moves out of the movement path of the needle 11 (21) and moves down froma position above and spaced from the upper surface of the sewing machinebed without being obstructed by the needle 11 (21) until the slot 61a(62a) in the pressure foot 61 (62) comes to the position opposite to themovement path of the needle 11 (21) whereupon the pressure foot 61 (62)presses the workpiece against the upper surface of the bed and as theabove mentioned piston rod 67a moves down, the intermediate pressurefoot 61 (62) displaces laterally of the movement path of the needle 11(21) in the direction opposite from that described above so as not tointerfere with the needle and moves upwardly. Thus, in the loweredposition, the intermediate pressure foot 61 (21) functions as anauxiliary device for the workpiece holding-down device and flapturning-over device and when the intermediate pressure foot moves backor upwardly after the operation of the thread cutter device, theintermediate pressure foot functions as a wiper device.

Now, the electrical control function will be described referring toFIGS. 17, 18 and 19.

FIG. 17 shows the block diagram of essential components of oneembodiment of the present invention. That is, ROM (read only memory) 68band RAM (random access memory) 68c are connected to a control circuit68a. And an operation table 69 is also connected to the control circuit68a through an I/O circuit (input/output circuit) 68d. Furthermore, theoutput of the control circuit 68a is connected through the I/O circuit68d to a motor 68e adapted to move the pressure foot based on a sewingpattern and to the above-mentioned flap turning-over device 31 (50)(FIGS. 10-13) and the outputs of the motor and flap turning-over deviceare connected to the above-mentioned sewing machine 10 (20).

FIG. 18 shows details of the above-mentioned operation table 69. Theoperation table 69 comprises display means 71, 72, a data input keygroup 73, switches 74, 75 for changing-over input data mode, lamps 76-83formed of LED for displaying input data mode, a switch 84 for inputtingpresence and absence of transverse seam, switches 85₁, 85₂ for inputtingsewing start position, switches 86, 87 for selecting sewing pitch inputdata and lamps 88-91 formed of LED for displaying sewing pitch to beinput.

FIG. 19 shows the flow chart of the control program for the sewingmachine of the present invention stored in the above-mentioned ROM 62.FIG. 19 shows the instance in which the left-hand end of the sewingpattern is the point of origin (reference point).

With the above-mentioned arrangement, sewing pattern data are stored inRAM 86c by the operation table 69. First of all, the type of data to beinput by the switches 74, 75 is selected. This is performed by lightingthe lamps 76-83 in succession from the lowermost lamp to the uppermostlamp by the switch 74 and lighting the lamps 76-83 in succession fromthe uppermost lamp to the lowermost lamp by the switch 75 so as to lightthe lamp or lamps corresponding to data to be input.

First of all, "pattern input" is selected and pattern No. is input bythe data input key group 73. The pattern No. is displayed on the displaycircuit 71. After the inputting of the pattern No., "longitudinaldirection length" is selected and the longitudinal direction length ofthe sewing pattern 92 (which is referred to merely as "longitudinallength" hereinafter) is input by the data input key group 73. Thelongitudinal length is displayed on the display circuit 72. And"transverse direction length" is selected and the transverse directionlength of the sewing pattern 92 (which will be referred to merely as"transverse length" hereinafter) is similarly input. The transverselength is displayed on the display circuit 72.

When the right and left ends of the sewing pattern 92 are backstitched,"right backstitch amount" or "left backstitch amount" is selected andthe number of backstitches is input by the data input key group 73. Andwhen the transverse direction 93 of the sewing pattern is sewn, theswitch 84 inputs transverse sewing "existence". And when the transversedirection 93 of the sewing pattern 92 is not sewn, the switch 84 inputstransverse sewing "absence". Furthermore, when the transverse direction93 is repeatedly sewn, the switch 84 inputs transverse sewing "presence"again.

And when the sewing pattern 92 is sewn from the left end thereof, theswitch 85₁ inputs and when the sewing pattern 92 is sewn from the rightend thereof, the switch 85₂ inputs.

And the switches 86, 87 input sewing pitch data. This is performed byselectively lighting the lamps 88-91 corresponding to sewing pitch to beinput.

The above-mentioned input sewing pattern data are in succession writteninto RAM by the control circuit 61 to be memorized therein.

When the zipper 3 is sewn on the workpiece with the flap as shown inFIGS. 1(A), (B) and (C), respectively, the flap may be the right flap(FIG. 1(A)), the left flap (FIG. 1(B)) or the center flap (FIG. 1(C)).When the zipper is sewn on the three types of flaps, respectively, inthe conventional sewing pattern automatic sewing machines, any one ofthe following four sewing patterns is required to be prepared and input.That is, (1) for the right flap, the sewing start point is the right endof the slider 3a on the zipper 3 (FIG. 2(B)) and the sewing machine sewsin the longitudinal direction from the sewing start point and then inthe transverse direction and finally in the longitudinal direction withthe left end of the slider 3a as the sewing termination point. This isthe first sewing pattern. (2) for the left flap, the sewing start pointis the left end of the slider 3a and the sewing machine sews in thelongitudinal direction from the sewing start point, then in thetransverse direction and finally in the longitudinal direction with theright end of the slider 3a as the sewing termination point. This is thesecond sewing pattern. (3) for the center flap, the sewing start pointis the left or right end of the slider 3a and the sewing machine sews inthe longitudinal direction from the sewing start point, skips thetransverse direction of the sewing pattern and then sews in thelongitudinal direction with the left or right end of the slider 3a asthe sewing termination point. This is concurrently the third and fourthsewing pattern.

However, in the sewing machine of the present invention, theabove-mentioned four different sewing patterns are not required to beprepared, but it is only required to determine the configuration of thesewing pattern (longitudinal and transverse lengthes) and input thesewing pattern together with the sewing start position and transversesewing existence and absence. That is, it is only required that for theleft flap, the left end sewing start position and transverse sewingexistence and absence are input, for the right flap, the right endsewing start position and transverse sewing presence are input and forthe center flap, the left or right sewing start position are input. Thisis one of the features of the present invention.

After data on the sewing pattern 92 have been prepared and input by theabove-mentioned procedure, when pattern number is designated and theactuation switch inputs the pattern number, the sewing pattern isautomatically sewn in accordance with the flow chart of FIG. 19 undercontrol of the control circuit 68a. That is, after the point of originprocessing and the general operation for converting input data into asewing pattern or the like (Block 100 in FIG. 19 which will be referredto merely as "Block" hereinafter), the characteristic action of thepresent invention is attained.

First of all, description will be made of the instance in which thesewing pattern for the left flap is input. The control circuit 68adetermines the sewing start position is at the left end or not (Block101). For the left flap, the sewing start position is at the left end.Next, the existence or absence of a backstitch at the sewing start pointis determined, and when the backstitch existence is input, leftbackstitch process is performed by the motor 68a and sewing machine 10(20) based on the input data (backstitch amount data ) (Blocks 102,103). Since the sewing start position is the left end, the motor 68e isthen rotated in the forward direction based on longitudinal length dataand the sewing machine 10 (20) sews the left-hand side longitudinallength to sew the left flap on (Blocks 104, 105). Next, a transversedirection sewing is performed by the motor 68e and sewing machine 10(20) (Blocks 106, 107, 108) based on transverse length data. When repeatsewing data are input, the motor 68e is rotated in the reverse directionand then the forward direction based on transverse length data andrepeat sewing is performed (Blocks 109, 110). Next, right-hand sidelongitudinal sewing which is concealed by the left flap is performed bythe sewing machine 10 (20) based on longitudinal length data (Blocks111, 112, 113) when the flap turning-over mechanism constituted by theflap turning-over device as shown in FIGS. 10-13 (the mechanism will bereferred to merely as "flap turning-over device 31 (50)" hereinafter)and is operated the motor 68e is rotated in the reverse direction. Whenbackstitch data at the sewing termination point (the right end) areinput, right backstitching is performed (Blocks 114, 115, 116). When thesewing pattern for the left flap has been sewn by the process describedhereinabove, for thread cutting and return to point of origin (referencepoint), the motor 68e is rotated in the reverse direction based ontransverse length data and then, transverse reverse skip and return topoint of origin for backlash₁ are performed (Blocks 117, 118, 119, 120,121, 122) to thereby complete the left flap sewing operation.

Next, description will be made of the instance in which sewing patterndata for the right flap are input. The control circuit 68a determinesthe sewing start position (Block 101). For the right flap, the sewingstart position is input as the right end. Therefore, the motor 68e isrotated in the forward direction and transverse forward skip isperformed based on transverse length data to set the sewing start pointas the right end (Block 123). When backstitch at the sewing start pointis input, right backstitching is performed by the motor 68e and sewingmachine 10 (20) based on the input data (Blocks 124, 115, 116). Next,when the motor 68e is rotated in the forward direction based onlongitudinal length data, the sewing machine 10 (20) sews rightlongitudinal length to sew the right flap on (Blocks 117, 105). Next,when transverse sewing and repeat sewing are input, the motor 68e isrotated in the reverse direction and then in the forward direction basedon transverse length data to perform transverse reverse sewing andrepeat sewing (Blocks 106, 125, 110, 111, 127). And when only transversesewing is input, the motor 68e is rotated in the reverse direction basedon transverse length data to perform transverse reverse sewing only(Blocks 106, 125, 126, 127).

Next, left longitudinal length sewing which is concealed by the rightflap is performed by the sewing machine 10 (20) when the flapturning-over device 31 (50) is operated and the motor is rotated in thereverse direction based on longitudinal length data (Blocks 112, 113).When backstitch data at the sewing termination point (the left end) areinput, left backstitching is performed (Blocks 114, 102, 103). When theright flap sewing pattern has been sewn by the process described justabove, thread cutting and return to point of origin are performed(Blocks 104, 118, 119, 122) to thereby complete the right flap sewing.

Next, description will be made of the sewing pattern when the sewingstart position is input as the left end. The control circuit determinesthe sewing start position (Block 101). Since the sewing start positionis input as the left end, when existence or absence of backstitch at thesewing start point (the left end) is determined and backstitch is input,left backstitching is performed by the motor 68e and sewing machine 10(20) based on the input data (Blocks 102, 103). Next, for sewing theleft flap on, left longitudinal length is sewn (Blocks 104, 105). Next,as to the center flap, since transverse sewing is input as "absence",thread cutting is performed (Blocks 106, 107, 128). Next, for sewing theright flap on, skip is performed based on transverse length data and thesewing start point for the right flap is set (Blocks 129, 123). Next,for sewing the right flap on, right longitudinal length sewing isperformed by the sewing machine 10 (20) based on longitudinal lengthdata when the flap turning-over device 31 (50) is operated and the motoris rotated in the reverse direction (Blocks 124, 112, 113). Whenbackstitch at the sewing termination point (the right end) is input,right backstitching is performed (Blocks 114, 115, 116). When sewingpattern for the center flap has been sewn by the process described justabove, for thread cutting and return to point of origin, the motor 68eis rotated in the reverse direction based on transverse length data andtransverse reverse skip and return to point of origin for backlash₁ areperformed (Blocks 117, 118, 119, 120, 121, 122) to thereby complete thesewing of the center flap.

Next, description will be made of the sewing pattern when the sewingstart position for the center flap is input as the right end. Thecontrol circuit 68a determines the sewing start position (Block 101).Since the sewing start position is input as the right end, the motor 68eis rotated in the forward direction based on transverse length data toperform transverse forward skip and the sewing start point is set as theright end (Block 123). When backstitch at the sewing start point isinput, right backstitching is performed by the motor 68e and sewingmachine 10 (20) based on the input data (Blocks 124, 115, 116). Next,the motor 68e is rotated in the forward direction based on longitudinallength data and the sewing machine 10 (20) sews right longitudinallength to sew the right flap on (Blocks 117, 105). Next, sincetransverse sewing for the center flap is input as "absence", threadcutting is performed (Blocks 106, 125, 126, 128). Next, for sewing theleft flap on, the motor 68e is rotated in the reverse direction,transverse reverse skip is performed and the sewing start point forsewing the left flap is set (Blocks 129, 120). Next, for the sewing-onof the left flap, left longitudinal length is sewn by the sewing machine10 (20) based on longitudinal length data when the flap turning-overdevice 31 (50) is operated and the motor 68e is rotated in the reversedirection (Blocks 121, 112, 113). When backstitch is input at the sewingtermination point (left end), left backstitching is performed (Blocks114, 102, 103). After the center flap sewing pattern has been sewn inthe manner mentioned above, thread cutting and return to point of originare effected (Blocks 104, 118, 119, 122) to thereby complete thesewing-on of the center flap.

With respect to the instance described just above, although it has beendescribed that the point of origin (reference point) of the sewingpattern is the left end of the sewing pattern, the same operativeeffects can be obtained even when the reference point is the right endof the sewing pattern and in this case, the rotational direction of themotor for transverse direction sewing is opposite from that of the motorin the previous instance.

As described hereinabove, according to the present invention, when aflap is sewn on a flapped workpiece, it is not necessary to prepare andmemorize a sewing pattern for accommodating a particular flap type andit is possible to automatically sew a flap in accordance with the typeof the flap when a sewing pattern configuration is prepared and input incombination with the sewing start point and transverse sewing existenceor absence.

Although preferred embodiment of the present invention have beendescribed hereinabove, many modifications and changes may be made on theembodiments without departing from the technological scope of thepresent invention. Thus, it is intended that the present inventionincludes all the inventive conceptions set forth in the attached claimsand the invention is not limited to the embodiments.

We claim:
 1. A sewing machine having a needle for use in sewing a zipperon a flapped workpiece, said sewing machine comprising a movable gripperassembly for clamping the zipper and workpiece in a side-by-siderelationship with the flap extending across the zipper, said gripperassembly including a base having an opening with longitudinallyextending sides, first gripper means extending along a firstlongitudinal side of the opening in said base for gripping a firstlongitudinally extending side of the zipper and the workpiece, andsecond gripper means extending along a second longitudinal side of theopening in said base for gripping a second longitudinally extending sideof the zipper and the workpiece, and drive means for moving said gripperassembly relative to the needle in a first direction along a first pathlength extending parallel to a longitudinal axis of the zipper with theneedle in vertical alignment with the opening in said base during thesewing of a first seam along one side of the zipper, for moving saidgripper assembly relative to the needle along a second path lengthextending perpendicular to the first path length, and for moving saidgripper assembly relative to the needle in a second direction oppositeto the first direction along a third path length extending parallel tothe first path length and the longitudinal axis of the zipper during thesewing of a second seam along a second side of the zipper, said firstgripper means includes a first member for pressing the first side of thezipper against said base, said second gripper means including a secondmember for pressing the second side of the zipper against said base,said first gripper means including a third member for pressing theworkpiece against said first member, said second gripper means includinga fourth member for pressing the workpiece against the second member. 2.A sewing machine having a needle for use in sewing a zipper on a flappedworkpiece, said sewing machine comprising movable gripper assembly forclamping the zipper and workpiece in a side-by-side relationship withthe flap extending across the zipper, said gripper assembly including abase having an opening with longitudinally extending sides, firstgripper means extending along a first longitudinal side of the openingin said base for gripping a first longitudinally extending side of thezipper and the workpiece, and second gripper means extending along asecond longitudinal side of the opening in said base for gripping asecond longitudinally extending side of the zipper and the workpiece,and drive means for moving said gripper assembly relative to the needlein a first direction along a first path length extending parallel to alongitudinal axis of the zipper with the needle in vertical alignmentwith the opening in said base during the sewing of a first seam alongone side of the zipper, for moving said gripper assembly relative to theneedle along a second path length extending perpendicular to the firstpath length, and for moving said grippe assembly relative to the needlein a second direction opposite to the first direction along a third pathlength extending parallel to the first path length and the longitudinalaxis of the zipper during the sewing of a second seam along a secondside of the zipper, said first gripper means including a first memberfor pressing the first side of the zipper against said base, said secondgripper means including a second member for pressing the second side ofthe zipper against said base, said first member is a firstlongitudinally extending leaf spring having an end portion which isfixedly connected to said base, said second member is a secondlongitudinally extending leaf spring having an end portion which isfixedly connected to said base, said first and second leaf springmembers cooperating with said base to hold the zipper against movementrelative to said base prior to gripping of the workpiece by said firstand second gripper means.
 3. A sewing machine as set forth in claim 2wherein said first gripper means includes a third member for pressingthe workpiece against said first member, said second gripper meansincluding a fourth member for pressing the workpiece against said secondmember.
 4. A sewing machine having a needle for use in sewing a zipperon a workpiece, said sewing machine comprising a gripper assembly forholding the workpiece and zipper against movement relative to eachother, drive means for moving said gripper assembly relative to theneedle while the zipper and workpiece are held against movement relativeto each other by said gripper assembly and control means for controllingoperation of said drive means and sewing machine to sew a first seambetween the zipper and workpiece along a first side of the zipper and tosew second seam between the zipper and workpiece along a second side ofthe zipper, said control means including data storage means for storingdata corresponding to the length of the first seam, the length of thesecond seam and the distance between the first and second seams, saidcontrol means including means for effecting operation of said drivemeans to move said gripper assembly relative to the needle in a firstdirection along a first path length extending parallel to thelongitudinal axis of the zipper through a distance determined by thestored data corresponding to the length of the first seam and foreffecting operation of said sewing machine to sew the first seam as saidgripper assembly moves in the first direction along the first pathlength, said control means including means for effecting operation ofsaid drive means to move said gripper assembly relative to the needlealong a second path length extending from one end of the first pathlength in a direction perpendicular to the first path length andlongitudinal axis of the zipper through a distance determined by thestored data corresponding to the distance between the first and secondseams, said control means including means for effecting operation ofsaid drive means to move said gripper assembly in a second directionopposite to the first direction along a third path length extending fromone end of the second path length parallel to the longitudinal axis ofthe zipper through a distance determined by the stored datacorresponding to the length of the second seam and for effectingoperation of said sewing machine to sew the second seam as said gripperassembly moves in the second direction along the third path length, saidgripper assembly includes first gripper means for gripping a firstlongitudinally extending side of the zipper and the workpiece and secondgripper means for gripping a second longitudinally extending side of thezipper and the workpiece, said gripper assembly including a base, saidfirst gripper means including a first gripper member for pressing thefirst side of the zipper against said base, said second gripper meansincluding a second gripper member for pressing the second side of thezipper against said base, said first gripper means includes a thirdgripper member for pressing the workpiece against the first grippermember, said second gripper means including a fourth gripper member forpressing the workpiece against the second gripper member.
 5. A sewingmachine as set forth in claim 4 wherein said gripper assembly includes abase, said first gripper member being a first leaf spring connected tosaid base for resiliently pressing the first side of the zipper againstsaid base, said second gripper member being a second leaf springconnected to said base for resiliently pressing the second side of thezipper against said base.